Measurement: Centimeters

Lesson Plan - Get It!

Audio:

• Did you know you can use a ruler or tape measurer to measure objects of different sizes?

During this lesson, you will learn how to measure with a ruler. Take out your ruler now.

Some rulers only have one side, but many have two sides like the one pictured below. You may notice that your ruler has two sides. One side of the ruler says, "IN" or "Inches" and the other side says, "CM" or "Centimeters."

This lesson is going to focus on using centimeters (CM) to measure small objects. Take a look at the centimeter side of your ruler.

• What number does it start with and what number does it end with?

The ruler above starts with zero centimeters (0) and ends with thirty centimeters (30).

If your ruler doesn't start with a zero, remember to always count up from zero anytime you measure. Sometimes, the zero is in the center of the ruler, so make sure you look for it!

Centimeters are part of the metric system. You can use centimeters to measure things that are small.

1. Explore your learning space and find at least three small objects.

2. Bring the three small objects to your table.

3. Choose one of your three objects to measure.

4. Place your object so the start of the object lines up with the zero (0) on the centimeter side of your ruler. You can look at the example below to help you.

• Can you see how the pencil tip is lined up at the zero?

5. Great! If you look at where the pencil ends (the eraser), you can see that it ends on seventeen. The pencil is seventeen centimeters long. Another way to write seventeen centimeters is to write "17 CM."

• How many centimeters was your object?

Say it out loud. Try measuring the remaining two objects, and say out loud how long each object is.

Don't forget to say "centimeters" after your measurement! It is important to state what unit you measured with so the person you are telling the measurement doesn't get confused!

When you are finished finding the measurements of the remaining two objects, move on to the Got It? section to watch a measurement video and play a measurement game.